Noise in Bassdrum decay

Discuss Nava construction and related issues
  • Could it be this ?
  • gihaume wrote:Could it be this ?
    Thanks, Gihaume. I'm currently unable to check my power supply (it is installed somewhere deep behind a rack). But I recall reading this thread, when I was building the Nava. So I'm pretty sure I took a power supply with >= 1A. But I indeed have a little bit of distortion on the mix out (only visible on the sine wave, almost impossible to hear). And I have installed the Extra9 Kit. However, the noise I recorded is on the individual BD out.

    So you don't have this noise in the decay phase of your unit? When recording the linked .wav file, the BD-decay was set pretty high (pot around 3 o'clock).
  • Finally I recall I had this. I probed the + and - 15v and found they had the small oscillation we hear on the bass drum. I could also hear it on the steiner parker filter.
  • gihaume wrote:Finally I recall I had this. I probed the + and - 15v and found they had the small oscillation we hear on the bass drum. I could also hear it on the steiner parker filter.
    Thanks Gihaume. I guess I'll have to play with another power supply. Maybe simply use a toroidal transformer instead of a wall plug.
  • I just tried out a toroidal transformer, 15VAC 2.667A. On load (Nava on and playing a pattern) I measure 18VAC @ 970mA.

    But still the same hissing on the BD decay. Gonna have to find something else.
  • I finally found the issue. This post helped me.

    In the Bassdrum section, cable 1 and 2 (noise decay in/out) leading from the Nava to the Extra 9 board, must not be bundled with the other cables. There's indeed a crosstalk from noise to audio.

    Simply separating these two cables and keeping them 2cm apart from the rest of the cables solves the problem!
  • flomo wrote: Nov 12th, '22, 17:34 My Nava has a noise floor in the decay phase of the bassdrum. I've recorded a .wav file here: https://florianmoser.ch/909-noise-decay.wav Buildnow GG

    It is recorded right out of the BD-output, but the noise is also there on the mix-output.

    Does anyone else have this issue?
    I'm having the same issue with noise floor in the decay phase of the bassdrum on my Nava! I listened to the .wav file you uploaded and it sounds exactly like what I'm experiencing.
  • I'm having the same issue with noise floor in the decay phase of the bassdrum on my Nava! I listened to the .wav file you uploaded and it sounds exactly like what I'm experiencing.
    It's most likely noise from the other cables. Try to separate cable 1 and 2 from the bassdrum section from the rest of the cables (keep it as far away as possible) and there should be no more noise.